Electrical feed-screw type linear actuators for sick beds/nursing beds raise and lower the bed or tilt the back section or knee section of the bed in order to lower the burden on patients living daily.
The sick bed/nursing bed is sometimes equipped with equipment called a CPR mechanism. The CPR mechanism is a device for making the bed return to a flat state in emergencies such as requiring cardio-pulmonary resuscitation operations.
This CPR mechanism must operate quickly and reliably whatever the circumstances, and must not restrict the operations of the linear actuator in a normal use of bed.
In this type of nursing beds equipped with a CPR mechanism, a cable joins an operating lever installed on the rear side of the back recliner plate to a release lever for canceling the operation of the anti-reverse mechanism in the linear actuator, and the release lever can be easily rotated in the release direction by gripping the operating lever and temporarily raising the back recliner plate in order to release the load acting on the anti-reverse mechanism (Refer to the patent document 1).
Linear actuators including CPR mechanisms include mechanisms where pushing the operating rod of a one-way clutch by the operating lever forces the one-way clutch to disengage (Refer to the patent document 2).    Patent document 1: Japanese patent Non-Examined Publication No. 2003-52762    Patent document 2: Japanese patent Non-Examined Publication No. 2000-253618